You will likely never shoot enough to see any difference - I have a friend who has a P226 (made in 1986) with 120,000 rounds through it and the last time he sent it to Sig for the FSP everything (including the barrel) was still within specs.
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If you take proper care of that barrel, keeping it clean and not using a steel brush or buggering it up otherwise, it is unlikely that you will have to worry about it wearing out unless you shoot 20,000 rounds through it every year and want to keep it going for 20 years. That might pose a problem. LOLHave a 226 with about 5K rounds thru it. Wat is the barrel life before it starts to degrade and accuracy or group sizes become effected?